Roasting time vs. temperature

[paulraphael]

I remember once seeing a graph that plotted times against temperatures. It allowed you to make an educated guess at what the time change would be if you tried roasting a bird at 475 instead of 450 (for example). Because of the physics of heat transfer, the graph was not linear, so it's not so easy to guess without it.

Does anyone know where I might be able to find this or something like it?

[ChrisZ]

I just looked in McGee's book, he says that cooking time is proportional to the thickness squared, or weight to the 2/3rd power, but no charts or graphs.

I have a few graphs bookmarked from sifting through the sous-vide thread, but they're all low temperature like this one.

[budrichard]

From a heat transfer perspective this is a three dimensional problem in heat flow and transfer which is not readily solvable without computer analysis. To make the problem somewhat simpler a cube could be used to approximate the shape of the bird and one could assume a constant surrounding external temperature. Looking at one extreme of a very small cube, the time temperature curve would vertical as the time difference would not matter. at the other extreme, if the cube were very large, the time temp curve would be horizontal as the cube temp would never change. An actual curve would be somewhere in between but without any idea of the specific heat capacity of the cube(bird), heat transfer coefficient at the surface, I wouldn't have the slightest idea of how to calculate this.

Best way would be to determine experimentally for your oven which of course does not solve the problem or answer your question.

Why not just use a temp probe?-Dick

[paulraphael]

I'll use a temp probe, but find them unreliable in chickens. Any conventional form of "cook it til it's done" will be fine.

I do have a theoretical interest in the nonlinear time/temp releationship.

It's possible that I hallucinated that graph. It's certainly nowhere in McGee, which is where I'd assumed it had been.